Self-piercing electrical connector plug



lIVlau'cl 30,A 1954 c. l. SMITH SELF-PIERCING ELECTRICAL CONNECTOR PLUG Filed Nov. 25, 1949 'n I7 INVENTOR ATTORNEYS y/ e 26 CHRISTOPHER LSMWH u Patented Mar. 30,1954

2,673,968 SELF-PIERCING ELgELIRICAL CONNECTR G Christopher I. Smith, Corona,

N. Y., assignor `to Leviton Manufacturing Company, Brooklyn, N. Y., a corporation of New York Application November 25, 1949, Serial No. 129,408

17 Claims.

The present invention relates to an electrical connector plug and relates more particularly to an electrical connector plug of the self-piercing type.

An object of the present invention is to provide an electrical connector plug that does not require the user to strip the insulation from the wires of a conductor cord in order to connect the wires to the contact elements of the plug thus making it possible for unskilled persons to attach the plug to a conductor cord quickly without the use of tools. Another object of the invention is to provide a connector plug of the selfpiercing type in which the various parts of the plug vcannot accidentally become separated and live contacts cannot be exposed while the plug is in use. A further object of the invention is to provide a connector plug of the self-piercing type that is suitable for use with various sizes of conductor cords.

Other objects and advantages of the invention will be apparent and best understood from the following description and the accompanying drawings in which:

Fig. 1 is a perspective View of an electrical connector plug embodying the invention showing the parts of the plug in position to receive a conductor cord;

Fig. 2 is a side View in section of the connector plug illustrated in Fig. 1 showing the parts of the plug with the conductor cord installed;

Fig. 3 is a side view in section of the connector plug as illustrated in Fig. 1;

Fig. 4 is an end View taken from the rear of the connector plug illustrated in Fig. 3; and

Fig. 5 is .an exploded view in perspective of the contact elements and conductor cord gripping jaws of the connector plug illustrated in Fig. l.

Referring now to the drawings in detail, there is an outer body or housing l0 of insulating material that is shaped so that it may be conveniently grasped by the user for inserting and withdrawing the plug from an electrical outlet. The body or housing Iii is hollow and is open at its front and back ends with a passageway I I extending lengthwise through it.

Slidably fitted within the passageway I I of the outer shell are two jaw-like members l2 and i3 of insulating material. The jaws i2 and I 3 are hinged or pivoted on each other at their forward ends which are normally located inside ofl In the illustrated embodiment,

the'housing the hinging or pivioting of the jaws I2 and i3 is accomplished by providing mating sections at the forward ends of the respective jaws. The

mating section on the jaw l2 is in the form of a projecting bead Iei that ts into a mating groove in the other jaw I3. Thus, when the jaws I2 and I3 are moved to the rear of the housing IE,

` the pivotal movement of the jaws permits them the portions of opposing faces between the :flanges from each other to form a passageway 8 between the jaws that is shaped to receive and position the end of the conductor cord It. A 'tooth i9 projects from the face of the jaw I2 and intermeshes with a cavity 2li in the face of the other jaw I3 when the ductor cord has the tooth is engages with the conductor cord It and forces it into the cavity 20 forming a U- shaped bend QI in the point, as shown in Fig. 2. in the conductor cord It tooth le and the sides of vides a strain relief that The U-shaped bend 2I is clamped between the will prevent stripping of the conductor cord from the plug by pulling on the cord alone.

The jaws I2 and I3 each carry a contact element 22. The contact elements 22 are each made from a single strip of electrically conductive mae" terial-that is folded back on itself at one end to form a connector prong 23 that is shaped to iit into an electrical outlet and is double the thick-v ness of the strip. The rearwardly extending end of the folded portion is flared outwardly to providea resilient projection 24 at the base of the prong that engages with one of a pair of recesses 25 in the front endof the housing l! when the jaws are fully inserted in the housing. The inner leg of the prong 23 is offset so that the resilient projection 24 may be moved out of engagement with the front end of the housing by pressing the projections inwardly.

The other end of the strip forming the contact 22 is bent to form two conductor piercing prongs or blades 2t and 21 that lproject from one face of he strip. The ends of the conductor piercing prongs are pointed and the points of the respec` tive prongs 2S and 2? are spaced transversely from each other, as shown best in Fig. 4, to insure that one oi the prongs will contact with the Wire in one side of the conductor cord it upon piercing the conductor cord regardless of whether a small or large diameter conductor cord is used. The' prong Zd is formed by bending' the end of the' jaws are closed. When the con-v been inserted between the jaws,

conductor cord at thisthe cavity 20 and pro` contact element 22 at right angles and the prong 21 is formed by bending a portion of the strip that has been severed along the side of the contact 22 at right angles. AS shown best in Fig. 3, the conductor piercing prongs 26 and 2l are U-shaped when viewed from the side, but the points of the prongs are offset laterally and transversely from each other. IThe conductor piercing prongs 26 and 21 on the respective contact elements 22 proj ect through openings 28 in the jaws I2 and I3 and extend at least halfway across the conductor receiving passageway I8 between the jaws on opposite sides of the passageway in order to penetrate the insulation and make contact with the wire in the respective sides of the conductor cord I6 when the jaws are closed.

In attaching the plug to a conductor cord, the resilient ends 24 of the prongs 23 are pressed inwardly to disengage them from the recesses 25 in the front end of the housing and then the Contact elements 22 and the jaws I2 and I3 are pushed rearwardly through the housing I0. When the jaws I2 and I3 project beyond the rear end of the housing, they are resiliently opened by the spring pressure exerted by the resilient ends 24 of the connector prongs against the inner walls of the housing I9. The end of the conductor cord is then inserted as far as possible between the open jaws, as illustrated in Fig. 1, and the jaws are then pushed forward into the housing I0 until shoulders 29 on the rear ends of the jaws I2 and I3 engage with the rear end of the housing I. The forward movement of the jaws closes the jaws and forces the conductor piercing prongs through the insulation and into contact with the wires of the conductor cord. It also brings the tooth I9 into engagement with the conductor cord forming the bend 2l in the conductor cord I8 with the cord thus being clamped and held between the jaws independently of the conductor piercing prongs.

When the jaws I2 and I3 have been fully moved forward relative to the housing I0, the resilient ends 24 of the connector prongs 23 spring outwardly and engage with recesses 25 in the front end of the housing I0 and prevent the contact carrying jaws from accidentally being moved relative to the housing so that live contacts cannot be exposed while the plug is in use. The ends 211 of the connector prongs 23 also engage with notches 30 in the walls of the passageway II when the contact elements 22 and the jaws I2 and I3 have been moved to the rear of the housing. This prevents the complete 'removal of the jaws I2 and I3 from the housing I0 as a result of their rearward movement.

As will be seen from the foregoing, the attachment of a connector plug embodying the invention to a conductor cord is extremely simple and can be made without the use of tools of any sort. In addition, after the plug has been attached, it is safe `as no live contacts can become exposed through accidental displacement of its parts. The plug also permits the use of different sizes of conductor wires such as are in common use. It will also be noted that the housing III and the. jaws I2 and I3 may be readily molded from suitable materials and that the contact elements 22 may be made from a. single strip of material. Thus, a connector plug embodying the invention can be made at a minimum cost.

It will be understood that various changes and modifications may be made in the illustrated embodiment of the invention without departing from the scope of the invention as defined by the following claims.

I claim:

1. In an electrical connector plug of the selfpiercing type, the combination of an outer housing of insulating material, said housing being hollow and having openings at its ends, a pair of jaw-like members having their forward ends slidably fitted within said housing, said jaw-like members pivotally engaging with each other at their forward ends with their opposed faces being recessed at the rear ends thereof to form a passageway shaped to receive a conductor cord and a contact element carried by each of the I jaw-like members, each of said contact elements having a conductor piercing prong at one end thereof and a connector prong at the other end thereof, said conductor piercing prongs extending into opposite sides of the conductor receiving passageway and said connector prongs extending beyond the forward ends of the jaw-like members and the front end of the housing.

2. In an electrical connector plug of the selfpiercing type, the combination as defined in claim 1 wherein the connector prongs of the contact elements have resilient portions at their bases that extend outwardly therefrom and engage with one end of the housing and the rear ends of the jaw-like members engage with the other end of the housing.

3. In an electrical connector plug of the selfpiercing type, the combination of a hollow housing of insulating material, said housing having openings at its front and rear ends, a pair of contact carrying jaws slidably fitted within the housing, said jaws pivotaily engaging with each other at their forward ends with portions of their opposing faces bein;f spaced apart at the rear ends thereof to form a passageway shaped to receive the end of a conductor cord, clamping means carried on the opposed faces of said jaws, said clamping means engaging with and clamping the conductor cord between the jaws, a contact element carried on the outside of each of the contact-carrying jaws between said jaws and the housing, said contact elements each consisting of a strip of electrically conductive material having a conductor piercing prong at one end thereof and a connector prong at the other end thereof, said conductor piercing prongs.

extending through the respective jaws and into the conductor receiving passageway, said connector prongs extending beyond the forward ends of the jaws and the front end of the housing,

' and yieldable projections carried by said connector prongs, said projections being located at the base of each connector prong and engaging with the front end of the housing.

4. In an electrical connector plug Yof the selfpiercing type, the combination as defined in claim 3 wherein the clamping means ronsists of a tooth projecting from the face of one of the jaws with the other of said jaws having a cavity in its opposing face into which said tooth extends.

`nector prongs piercing type, the combination as thereof Vto form a passageway shaped to receive the end of a conductor cord, and contact `elements carried by each of the jaws, a conductor piercing prong carried at one end of each of the contact elements, the conductor piercing prongs of the respective contact elements having pointed ends projecting into the passageway between the opposed faces of the jaws on opposite sides thereof, said contact elements being folded at their other end to form connector prongs, said connector prongs extending beyond the forward ends of the jaws and the front end of the housing, the inner legs of said connector prongs being offset inwardly and the rearwardly extending ends of the outer legs of said conproiecting outwardly at the base of said prongs, said outwardly projecting portions being resilient and engaging with the front end of the housing when the contact elements and the jaws are inser-Sed within the housing, said housing having notches on the inner surface thereof adjacent the rear end of the housing, said notches being positioned to engage with the outwardly proiectingr ends of the connector prongs upon rearward movement of the contact elements and the jaws.

6. In an electrical conductor plug of the selfdefined in claim 5 which includes intermeshing portions on the opposing faces of the contact carrying jaws, said intermeshing portions engaging with the clamping of the conductor cord between the jaws independently of the contact elements.

7. In an electrical connecter plug of the selfpiercin'f type, the combination of a hollow housing of insulating material, said housing having an opening extending therethrough from the front to the rear thereof and notches in the inner surfaces thereof, a pair of contact-carrying jaws slidably tted within the opening in the housing, said jaws pivotally engaging with each other at their forward ends with portions of their opposed faces at their rear ends being spaced apart to form a passageway shaped to receive the end of a conductor carried bv each of said jaws, said contact elements each consistin".r of a strip of electrically conductive material having a conductor piercinf.r prong at one end thereof and a connector prong at the other end thereof, said conductor piercinr prongs extendinfr through the jaw carrying said contacts into the conductor receiving passageway on opposite sides thereof, said connector pronffs extending beyond the forward ends of the iaws and the front end of the housi f ing and yieldable proiections carried by the connector prongs, said projections extending outwardly from the prongs at the bases thereof and engaging with the front end of the housing when the iaws are inserted in the opening in the housing and with the notches in the inner surfaces of the housing when the jaws are moved to the rear of the housing. l

8. In an electrical connector plug of the selfpiercing type, the combination of a hollow housing of insulating` material, said housing having an opening extending therethrough from thfe front and the rear thereof and notches in the inner surfaces thereof, said notches being located at the rear of the housing, a pair of contactcarrying jaws sldably fitted within the housing, said jaws pivotallv engaging with each otherat their forward ends with portions of their opposing faces being spaced apart at the rear ends thereof to lform a passageway cord, a contact element shaped to receive i.

the end of a conductor cord, clamping means carried on the opposed faces of said jaws, said clamping means engaging with and clamping the conductor cord between the jaws, a contact element carried by each of said jaws, said contact elements each consisting of a strip of electrically conductive material having a conductor piercing prong at one end thereof and a connector prong at the other end thereof, said conductor piercing prongs extending through the respective jaws and into the conductor receiving pasageway, said connector prongs extending beyond the forward ends of the jaws and the front end of the housing, and yieldable projections carried by said connector prongs, said projections being located at the base of each connector prong and engaging with the front end `of the housing when the jaws are inserted in the opening in the housing and with the notches in the inner surface of `-he housing upon move- 'ment of the jaws to the rear of the housing.

9. In an electrical connector plug of the self- -piercing type, the combination of a housing of insulating material, said housing having an opening extending therethrough, a pair of opposed contact supporting members of insulating materia-l slidably fitted within the opening in the housing, said members being pivoted on each other at their forward ends and being swingable toward and away from each other upon movement into and out of the housing, the opposing `faces of said members being recessed and defining passageway to receive the unstripped end of a conductor cord, said passageway being open at the rear of said members, clamping means on the opposing faces of said contact supporting members engaging with and holding the end of 'a conductor cord in said passageway, and a contact element carried by each of said members, each of said contact elements including a connector prong at one end thereof and a conductor piercing prong at the other end thereof, the connector prongs extending beyond ends of the contact supporting members and the housing when the contact supporting members 'are inserted in the housing, the conductor piercing prongs on the respective contact elements lextending into the conductor receiving passage- Vway on opposite sides'of the center line thereof.

10. In an electrical connectorplug of the selfpiercing type, the combination of a housing of insulating material, said housing having an opening extending therethroug a pair of op- -posed contact supporting members of insulating `material slidably tted within the opening in the housing, said members beingpivoted on Yeach other at their forward ends, the opposing faces of said members being recessed and deiinin'g a passageway to receive the unstripped and unseparated end of a twin conductor cord, said passageway being open at the rear of said members, a contact element carried by each of said members, each of said contact elements including a connector prong at one end thereof and a conductor piercing prong at the other end thereof, the connector prongs extending beyond the forvward ends of the contact supporting members, the conductor piercing prongs on the respective contact eiements extending into the conductor receivingpassageway on opposite sides of the center line thereof and clamping means carried by said members, for clamping the end of the conductor cord in said passageway, said clamping means and the conductor piercing prongs being movable into and out of engagement with ,the conductor cord upon movement tact carrying members into and out of housing.

1l. In an electrical connector plug of the selfpiercing type, the combination of a housing of insulating material, said housing having an opening extending therethrough, a pair of opposed contact supporting members of insulating material slidably fitted within the opening in the housing, said members being pivoted on each other at their forward ends and being swingable toward and away from each other upon movement into and out of the housing, the opposing faces of said members being recessed and denning a passageway to receive the unstripped and unseparated end of a twin conductor cord, said passageway being open at the rear of said members and a contact element carried by each of said members, each of the conthe of said contact members including a connector prong at one end thereof and a conductor piercing prong at the other end thereof, the connector prongs extending beyond the forward ends of the contact supporting members and the housing when the contact-supporting members are inserted in the housing, the conductor piercing prongs on the respective contact elements extending into the conductor receiving passageway on opposite sides of the center line thereof.

12. In an electrical conenctor plug of the selfpiercing type, the combination of a hollow housing of insulating material, said housing having openings at its front and rear ends, a pair of opposing contact carrying jaws having their forward ends slidably fitted within the housing, said jaws pivotally engaging with each other at their forward ends with portions of their opposed faces being spaced apart at the rear ends thereof to form a passageway shaped to receive the end of a conductor cord, a contact element carried on the outside of each of the jaws, said contact elements being located between the respective contact-carrying jaws and the housing and each consisting of a strip of electrically conductive material having a pair of conductor piercing prongs at one end thereof and a connector prong at the other end thereof, said conductor piercing prongs extending through the respective jaws and projecting into the conductor receiving passageway on opposite sides of the center line thereof, each pair of conductor piercing prongs having points that are spaced transversely and lengthwise with respect to each other, said connector prongs extending beyond the forward ends of the jaws and having yieldable projections extending outwardly therefrom, said projections releasably engaging with the front end of the housing when the jaws are in a forward position in the housing and resiliently engaging with the inside of the housing when the jaws are moved rearwardly thereof, said projections engaging with the inside of the housing at a point beyond the pivoted ends of the jaws and urging the rear ends of the jaws apart upon engagement with the inside of the housing.

v13. In an electrical connector plug of the selfpiercing type, the combination of a housing of insulating material, said housing having an opening extending therethrough, a p-air of opposed contact supporting members of insulating material slidably fitted within the opening in the housing, said members being pivoted on each other at their forward ends and having opposing faces swingable toward and away from each otherV upon movement into and out of the housing, the opposing faces of said members being recessed and defining a passageway to receive the unstripped end of a conductor cord, said passageway being open at the rear of said members and a contact element carried by each of said members, each of said contact elements including a connector prong at one end thereof extending beyond the forward ends of the respective contact supporting members, said connector prongs extending beyond the forward end of the housing when the contact supporting members are in a forward position in the housing and a pair of conductor piercing prongs located at the other end o-f each of the contact elements, the prongs on each of the contact elements being spaced laterally and transversely with respect to each other on the respective contact elements with the prongs on the respective contact elements extending into the conductor receiving passageway on opposie sides of the center line thereof.

14. In an electrical connector plug of the selfpiercing type, the combination of a housing of insulating material, said housing having a front and a rear end with an opening extending between said ends, a pair of opposed contact supporting members of insulating material, each of said members having an inner and an outer face and a forward and a rear end, the forward ends of said members being pivoted on each other and slidably fitted within the housing with the rear ends thereof being movable toward and away from each other upon movement of the members into and out of the housing, the inner faces of said members opposing each other and being recessed to deflne a passageway to receive the unstripped end of a conductor cord between said members, said passageway being open at the rear of said members and a contact element carried on the outer face of each of said members, each of said contact elements consisting of a strip of conductive material having a connector prong at one end thereof, a conductor piercing prong extendingr into the conductor receiving passageway at the other end thereof and a resilient locking member extending outwardly from the connector prong, said connector prongs extending beyond the forward ends of the contact supporting members and beyond the fro-nt end of the housing with the resilient locking members relea-sably engaging with the front end of the housing when the contact supporting members are inserted in the housing, said resilient members engaging with the inside of the housing at a point beyond the pivoted ends of the contact supporting members and resiliently urging the rear ends of said members away from each other upon movement of said members rearwardly of the housing.

15. In an electrical connector plug of the selfpiercing type, the combination as defined in claim 14 wherein each of the contact supporting members has an opening extending through said member from the outer to the inner face thereof and through which the conductor piercing prongs of the Contact element supported thereon extends, the openings in the respective members being located on opposite sides of the center lines of said members.

16. In an electrical connector plug of the selfpiercing type, the combination of a housing of insulating material having an opening therein, a pair of contact-carrying members slidably mounted in said opening, said members having inner and outer faces with the outer faces thereof engaging with the sides of the opening in the housing and holding the inner faces thereof in opposing relation, said inner faces having re cesses therein :shaped to receive an unstri'pped end of a dual conductor cord between said members, each of said members having an opening extending therethrough at right angles to and communicating with one half 4of said recess and a contact element carried by each of said inemcesses in said members, each of said strips including :a comiector element and having a conductor-piercing prong projecting from one face Isaid conductor-piercing prong having -a pointed end extending through the opening in one of the contact-carrying members to at least the top of the recess therein.

17. In an electrical connector plug of the selfpiercing type, the combination as dened in claim 16 wherein each of the contact elements has a CHRISTOPHER I. SlVIITH.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Monosmith Jan. l0, 1911 Gilbert Apr. 24, 1934 Gilbert Jan. 19, 1937 Brainard May 19, 1942 Cottrell Sept. 24, 1946 Cook Sept. 27, 1949 Levitt July 8, 1952 FOREIGN PATENTS Country Date Italy Oct. 24, 1947 Greafirtain-: Apr. 26, 1949 

